Suspected Malignant Lesion of the Hip Resolves after Parathyroidectomy: Osteitis Fibrosa Cystica (or Brown Tumor): A Case Report.

We present a case of osteitis fibrosa cystica (OFC), also known as "brown tumor." A 55-year old female was admitted to the hospital with several months of right hip pain that was becoming more severe. A malignant lesion of the pelvis was suspected after initial imaging studies. Significant hypercalcemia led to a diagnosis of hyperparathyroidism and ultimately a benign parathyroid adenoma. Surgical excision of the adenoma resulted in full resolution of the tumor in her pelvis as well as her pain. It is important to keep OFC, or brown tumor, in your differential diagnoses when presented with a bone lesion.